Generation of fractional optical vortex arrays via controlling the forked photonic lattices in a single spatial light...

Optical vortices and vortex arrays with spiral-shaped wavefronts and theoretically infinite orbital angular momentum (OAM) have potential applications in high-capacity optical communications and computing, optical micro manipulation and other fields. In this work, generation of vortex-beam arrays is studied by using the forked-photonic lattices in a liquid crystal spatial light modulator (SLM). Via adjusting the holograms of forked-photonic lattices, the input Gaussian beam travels through this lattice, experiences phase superposition and is diffracted into vortex arrays of different OAM. Vortex arrays of the same integer, same fractional and different fractional OAMs along the x and y directions are experimentally generated and analyzed, which shows good additivity in all directions and OAM property during propagation. This work suggests a flexible way for generating fractional optical vortex arrays, and implies application in the fields of optical manipulation, optical communication and quantum information processing.